Gunnery practice range control device



Nov., 28, E950 C. W. CLARKSON, JR

GUNNERY PRACTICE RANGE CONTROL DEVICE Filed Dec. 27, 1945 .IgG-...2-

AUT SIGHTING TARGET' START 4 Sheets-Sheet 1 STATIONARY SCORING I TARGET.

i -\NsTRucToRs STATON- -59 64 r BY Z mp HTo/ENEYS NOV 28, 1950 c. w. cLARKsoN, JR

GUNNERY PRACTICE RANCE CONTROL DEVICE Filed Deo. 27, 1945 4 Sheets-Sheet 2 D N H ummm Nov. 28, 1950 c, w, CLARKSON, JR 2531,40@

GUNNERY PRACTICE RANGE CONTROL DEVICE Filed Dec. 27, 1945 4 Sheets-Sheet 3 Nov. 28, 1950 C. W. CLARKSON, JR

GUNNERY PRACTICE RANGE CONTROL DEVICE 4 Sheets-Sheet 4 Filed Dec. 27, 1945 KOPO:

m@ 0 Vm W wm A E C www m @w Patented Nov. 28,

UNITED sii-Aras GUNNERY PRACTICE RANGE CONTROL DEVICE (Granted under the act of March 3, 1883, as MjfiemleflApril so, 192s; 37o o. G. 757) l The invention describedheren may be mannfactured and used by or for the Government" for governmental purposes Without payment to of any royalty thereon.

This invention relates to improvements in control Adevices for aircraft gunnery practice ranges, and more particularly to control devices ifor eff? footing an automatic operational control of the aircraft gunnery range apparatus. f lThese gunnery Vprmtice ranges each include a platform mounted for rotation about 'a fixed airis, o r the agis of/the platform may bemontnted for tilting movements in a vertical plane, in addition to the aforesaid rotative movements.

The platform simulates the 'body' of an aircraft, such as a bomberjand has -a directional vgun pint, or a complete aircraft gun turret mounted .theref on, the gun unit or turret being capable of iptaf tion with the platform, and 'independent rotation under the control of a gunner Within the turret, incident to the training of th gun n nit or turret on a sighting target. Rotation of t-l'ie platform, and tilting thereof, if the tilting provision incorporated, is by suitable power drive means under the control of a gunnery instructor or other operator in an. instructorfs station, preferably located at one vside of Athe platform beyond'the, connes thereof. A

The sigh-ting target is `preferably in the form of a miniature target airplane depending ,from .a carriage that travels on a 4traclf:frame inclined above the line of vfire from the guns when trained in a substantially horizontal position, with the line of travel of ythe sighting'targetparallel to the track frame ina vertical plane, preferably tov/ard n the laxis of rotation of the turret and 'in the plane of the gun sightingV means when the ,gunfs are horizontal. Power meansis provided for moving this sighting target toward-the turret. kManually adjustable con-trol means is alsopro'vided attite aforesaid instructors station for controlling the movement of this sighting target along the track, independently of .turret ,or platform'rotation'."

In completing this brief description of this known gunnery practice range, a scoringmeans is provided `for determining lthe Vaccuracy ofth'e gunners sighting operations. This preferably comprises a stationary scoringv target 'having scoring fbulls eyes thereon, one Afore'aohv'of'tlie guns, when a Amulti-ple control unit isemployed These scoring targets maybe spaced apart laterfally so that each bulls eye is centered in the line of re of one of the guns Whichis carried by the turret, .or gununit, and this scoring vtarget-is located ibelow .the inclined Aplaneof movement of 2 the sighting target so that live ammunition in the hg-ins'canfb used to register on the scor target" Without stri g ths'ight-ing targetiv Assuming that a g aiming the guns, having conventional gun Thts ythereon that have benpreviousfly adjusted t'theplane of move@ ment :ofthe sighting 'target while' the gims ere boresig-hted Aon the'stier-ing target, proper' slgntf ing'o'f the guns and firing' thereof vWill score on the bols eyeswregardles's of any rotational or tilting rmovements of the ysulfportingl platform. A' Roanne ih naar ebt-ever. tv-frag' *1r-.e movement of the ysightingY taiget tovvardthe'gnfner, when observed through'tl'ie ,g1/ insight means, simulates"aoompunfforward and lateral m er ment of the sightrig" tardif-it.V to*l rdl the'gii ner. This produces the effect of'a suit planeflyirilg toward the ygurneras'he sf hts the glins on: the ',hsositio bemgthat cfa g n; asaltantes in v nt, Relative' manges inthe rates' of rotation of 'ne platform and speed of travelof the sighting get ytmf/.ald' 1116 gunnerv simulates' dziler v irl-ite, pu'r'suiturv suchr'as vvojild i by sie isf-ifea 'piane effi @man @betonte from different'anglesf -The'instriotoi'fmanipulating the rplatforrn and sighting trgft'contro ay yary or adjjngsftithe rs'pectivewpvvernm platform ea-ns for the sigh-ting Atarget5to"mo'v'e' the' sighting' t'gnget,Z rotate the platform at any desired ifelativera v 'My Virri'pro'v'em'eii'fcomprises means for af of matically' predterminig the respectiye rat s of movements of 'the 'platform ,and 'the target planefinorderzp 'sirnulfativi/ith4 prec` n, a predetermined riunita tf diffrent, ,denn pursuit Crvesb'eing'flovfn by atta'ekingp r'- suit -plane','res'prese"' tatiye of attacks on a bomber from diri-trent "iespana wifliielmysisbislir'e' in; details of yc'onlstrnotion igelatilg ting and searing t "et structures, no clail is QrfnaleA r'holein tio 4anyno contained in :thse speciiricelerinenta my invention being the r'control W means rfor effecting 'the ini dividu'afl and-relative movementsof therespective eiements'atomaticgiiy with'predision so matan ineXperienfd bneritr aim instructors @Q'nttl station 'main-by the vmyan'ipulationV offcertain 'c'qn- An object of the present invention, therefore,

is the provision of control means for rotating the platform at a plurality of predetermined different rates, and for moving the sighting target toward the gunner at a plurality of predetermined different rates.

A further object is the provision of a plurality of platform rotation control devices, each of which rotates the platform at a predetermined different speed and control means for selectively connecting any of said control devices to the platform for determining the rate of rotation thereof.

A further object is the provision of a plurality of platform rotational control devices, each being operable to rotate the platform at a different predetermined rate, together with a second group of sighting target control devices, each being operable to cause movement of the sighting target toward the platform at a different predetermined rate, and means for simultaneously connecting a predetermined pair of said platform and sighting target control devices, respectively, to the platform and sighting target power operating means for predetermining the relative rates of movements of the platform and the sighting target.

A further object is the provision of a plurality of individually selectable control devices, located at the instructors station for simultaneously causing rotation of the platform and movement of the sighting target toward the platform at definite predetermined ratios for simulating the relative movements between a bomber, and a pursuit plane when attacking a bomber from different predetermined angles with respect to the longitudinal axis of the bomber.

Other objects and advantages of this invention will become apparent from the following description., taken in connection with the accompanying drawings, in which like reference characters refer to like parts in the several figures.

Fig. 1 is a somewhat diagrammatical perspective view of an exemplary form of aircraft gunnery range practice range, illustrating my improved control apparatus applied thereto, and located at the instructors control station, the improved control device being shown in elevation. Fig. 2 is a fragmentary plan view of a portion of the. interior of my improved control device, as illi'strated in Fig. 1, disclosing several sets of the platform and sighting target movement control elements and the common timing motor drive means therefor.

Fig. 3 is a fragmentary view in elevation, of one pair of the control devices, as seen in Fig. 2, and its associated switch devices for initiating the aforesaid control devices into operation.

Fig. 4 is a vertical sectional view, taken approximately on the plane indicated by the line 4 4 in Fig. 2, illustrating one of the switch devices, and one of the adjustable control devices with its associated operating cams,

Fig. 5 is a schematic wiring diagram of my improved automatic control system.

Referring to Fig. 1, the aircraft gunnery range practice apparatus comprises a gunners ring station A, a sight target unit B, a scoring target unit C, and an instructors control station D. A xed base I is provided, or the base I may be tiltable about a horizontal pivot if changes in elevation between the pursuit plane and the bomber are to be simulated. The base I carries a supporting platform 2 which is rotatable thereon about a xed axis, by power means such as a motor 3 which drives a gear train 4, meshing with a ring gear 5 disposed around the platform.

A directable gun unit is mounted on the platform 2, for independent rotation about the turning axis of the platform. This unit may be a complete aircraft gun turret and supporting base structure, as illustrated at 6, with the turret 'I carrying the guns 8, and rotatable on the turret base with the guns 8 adjustable in elevation. A motor 9 is fixed on the platform .2, and carries a worm I0 which meshes with a large worm gear Illa secured to a vertical shaft I lib rotatably journalled on the vertical axis of the platform. A gun mounting bracket is fixed to this shaft IDb and pivotally carries the guns 8, for adjustments in elevation. The turret is connected for rotation with the shaft Ib and carries a control handle for power rotation of the shaft and turret in azimuth, the handle operating a slider contact IIa to vary the effective electrical power from a battery IIb for rotating the turret, through resistance IIc, and the conductors IId and IIe, connected to the conventional poles of the reversible motor 9, the conductor II f completing the circuit between the motor 9 and the battery IIb.

With the adjustable contact IIa in mid-position as shown, the two effective portions of the resistance I Ic are equal and the potential to the opposing fields of the motor 9, through the conductors IId and IIe, is equal, preventing rotation of the gun standard or post IDb carrying the guns, and the turret head secured to the post. Movement of the handle up and down varies the two portions of the resistance IIc at the opposite sides of the slider contact IIa, controlling the direction and the rate of rotation of the guns 8 and the turret in azimuth. Limit switches IIg and Ilh break the connections IId and IIe to the motor 9 when the turret and guns are swung too far in azimuth off of the scoring target.

The guns 8 are elevated and depressed electrically, by power means under the control of the gunner, in a similar manner. A reversible motor I2 is fixed to the turret structure, and may be carried by the central standard or post Ib for the guns. The opposing fields of motor I2 are connected by conductors I2a and I2b to a resistance bridge I2C, Whichis engaged by a slider contact I2d, connected to one terminal of the power source or battery IIb, while the other battery terminal is connected by a conductor I2e to the center pole or common return for the motor I2. Movement of the slider contact I2d up or down, by a gunner within the turret, causes the motor I2 to rotate in one direction or the other, rotating a worm I3 which meshes with a worm segment I3a, secured to the tiltable gun mount, causing the guns to be elevated or depressed as desired. The two slider contacts I2d and IIa, therefore, control the training of the guns 8, independently of any rotational movement of the supporting platform 2 by the instructor or operator in the instructors station D.

The stationary scoring target C is mounted on suitable supports I'I and carries two bulls eyes I8, preferably located in a vertical plane at right angles to the line of re of the guns 8 when trained horizontally. The spacing between the bulls eyes is such that the line of fire from each gun will register in the center of each target when the guns are properly trained on the scoring targets. The stationary scoring target C is located at any suitable distance from the guns, depending on the size of scoring targets employed, the distar-ice` being preferably about 1,000 inches.l

The' sighting targetf B,` employed* in the gune nery practice range,- comprises a rigid frame i9, having an endless carriage guide track 29 on which a carriage is mounted. The carriage'.V is driven by a fiexible member such as a cable 23, tra-ined around a pair of idler pulleys 24 and 25 and' a-thirdv driving pulley 2S. The'y driving pulley 26 is driven by a gear 211,-. meshing with a gearv 28 that is fixed on the drive shaft of a ree versible motor 29. The direction ofrotation of the motor and its speed is controlled at the in*- structors control station D.

'Ehe sighting target frame 4Il) is laterally adjustable above, and in front of theturret, when the guns are trained on the scoring target C, suitable adjustable supporti-ngmeans being provided Vsuch as indicated at 30, having their lower ends xed: to the sighting frame and their upper endsv adjustably secured in the arcuately slotted supports 3l. Y V

The sighting means for the guns with-in the turret may be of any conventional type, either an optical gun sight, or an open gun sight as shown, comprising a front bead [Sand a rear multiple ring or rad sight It, with the sighting axis elevated above the scoring target, when the guns are trained on the bulls eyes thereof.- The sighting frame carriage track is positioned in a parallel plane elevated above the sighting plane. A sighting target 32., in the form of a miniature airplane, is dependingly carried on a light rod 33, secured to the carriage 2l. VThe inclined path of movement of the sighting target airplane 32 is located in the sighting axis of the Agun sight, when the guns are trained on the scoring target C,Y and the sighting airplane or target 32 is positioned so that the travel thereof is also in a vertical plane passing through the sighting axis of the sighting means, with the guns trained in azimuth on the vscoring target, although to simulate actual conditions, where a certain amount of lead is to be calculated by the gunner, as when using special radv sights, the sighting frame i9 may be adjusted laterally, to dispose the reach of the guide track on which the carriage travels toward the turret, at one side of the turret and platform turning axis. The aforementioned structure comprises a typical aircraft gunnery practice range to which my improved control apparatus is applied. In the aforementioned typical arrangement two control knobs 311 and l35 are provided at the control station D, for controlling the respective speed ratios of the `sighting target motor 29, and the rate of turret rotation by its motor.

In order to properly simulate any sighting problem, at least three variable factors must be taken into consideration, assuming that the aircraft which is simulated by the platform is traveling on a straight course. rIhe first is the speed of the aircraft carrying the gunner, represented by the supporting platform 2; second, the speed of the approaching pursuit plane which is represented by the movement of the sighting 'target plane 32 toward the laxis of the platform; and third, the direction of attack with respect to longitudinal axis of the bomber carrying the guns, as represented by the platform. From 'the' above it will be noted that it requires an experienced instructor to `Ymanipulate the two control knobs St and 35 to properly control the turret and sighting target movements to correctly rov Simurate, due to tnecompcund. platformy and. sighting target movements; the' proper pursuit. k

curve' flown by the attack-ing` plane'. It is.I doubtful: that even an experienced instructor cou-ld identically'control: the relative movements of thieplatform and sightl target for' av great number of. successive similar tests: `or' problems, and there' fore; he could 4not afford equal and uniform tests to all candidates that are being. tested.`

The: speeds of the' two motors 3 and. 29Y were formerly controlled by two potentiometers, the relative adjustment o'f which, during the gunnery' practice., determined the relative acceleration and' speeds of* the platform and sighting target, simulating-an attack of an` enemy' pursuit plane dying' diiferen-t pursuit curves from different attack angles toward the `gun-ner withinfthe turret of "aboiriber.

in my improved control system the aforesaid manual control is 'also included, with switch means for disconnecting the manual cont-rol when Vimproved automat-'ic control is initiated. Re= ferring now to the Wiring diagram in Fig. 5, diagrammati'cally illustrating my control syste.l the sight target motor' Eiland platform motor 3 are of conventional types, designed to' operate at different predetermined speeds, depending upon the amount of current supplied to them, and' com'- monly known in the trade as the ampldyne' type of drive consisting' ofthe usual motor-generator sets 29a 291), and 3a, v3b, Where the motors 29h and 3b are connected to any separate power source not shown, the .generator 29a having a generator field 2`9`c connected through the conductors $5 and 51 tothe manual control potentiometer device 5I, or through the switch device 33 to the automatic control potentiometers $3. The generator eld 3c of. the generator Baisv connected by conductors 54 and'5` to the .manual con-trol potentiometer 5i), or through the control .switch 42 to the automatic control potentiometers 53. The electrical outputs from the respective generators, 29a and 3a, as controlled by the elds 23e and 3c are connected to thersighting.- target motor 29 andthe rotary platform motor. Changesfn the amplitude or potential of the current applied to the controlelds 28o and 3c,fof course, changes" the amplitude and potential of thecurrent in the fields 2M and 3d of themotors 29 and 3, thus controlling thespeed. and direction oflrotationo the sighting target advancing motor .29 andtherotary platform motor 3. The amplidyne Ycon-- trol is well known and lforms no part of the vinvention, and 'in fact, simpler reversible motors might beconn'ecteddirectly to the potentiometers indicated above if the in'ductancesand resistances in the potentiometers were madefsuicient to` directly control the `electric motor vinput currents. Current is supplied to thel control system atl' and 41| from any suitable source.

During the manual control the two manualautomatic switches 42 andfli', respectively, :cone trolling'theplatform and track motors, are-moved clockwiset'o positions "Maand 'li-3a. Current from the Vsource 40 and'dl passes through the terminal blocks 44, 45, 41 land 48, and the action-.switch its when closed, to the manuallysettable potentiometers la'nd 451 lforthe vplat'formand' sig'llti'ngitar-` get control, the potentiom'etersfbeing adiustable by the respectivevcontroI knobs 35 'andi-34i on the front of the action control -boxat the instructors station, as seen in Fig'. `1. The "twoliinitfswitches i I g and fl lh areconne'cted--in thefplatform` meter circuit from the terminal llock 54'8 land limit tthe degree ofazi'muth deflection of the guns with respect to the scoring target.

Counterclockwise movement of the two switch devices 42 and 43 from their manual positions 42a and 43a to automatic control positions 42h and 43h, disconnects the circuits to the two manually operable potentiometers 50 and 5| and connects the conductors 52 and 53 to two groups of automatically operable potentiometers.

Referring to theface or front ofthe control panel at the instructors control station D, legends have been applied to the various control elements. Under manual control when the sighting target and rotatable base control knobs 34 and 35 are in vertical position, as shown, and the automatic toggle switch is down, the two switch elements 42 :and 43 in the wiring diagram are in the positions indicated at 42a and 43a, with the slider 52 and 53 of the potentiometers 53 and 5| in mid-position. r`Ehe potentiometers have center taps from which conductors 54 and 55 lead to one operating 'terminal respectively of the control fields 3c and '25e for the platform rotating motor and the sight 'target motors 3 and 2S. Conductors 55 and 5l connect the other terminal of each of the control :fields 3c and 25e for the platform rotation and sight target moving motors 3 and 29 to the central or slider contacts 52 and 53 of the respective manual base and track control potentiometers. Manipulation of the control-.knobs adjusts the sliders 52 and 53 to vary the current potential delivered to the motors 3 and 29 through the conductors 54 and 56, and consequently varies the speeds of movements of the sighting target plane and the platform.

When the two switch elements 42 and 43 are moved to theautomatic control position, as illustrated at 4'219 and 43h in Fig. 5, the circuits between the manually operable potentiometer sliders 52 and 53 and the motors 3 and 25 are interrupted and the conductor 55 is then connected to a conductor 56a, having a plurality of branches or conductors 55h, 56h, leading respectively to a series of automatically operable potentiometers 58, for the 90, 45, 22.5, 11.25 and 0 angle simulated attacks. Each of these branch conductors has a control switch 55 therein as shown in Figs. 1 and 5 later to be described. These switches are normally open, and the closing of any of them connects the slider 65 of the selected attack angle control potentiometer 58 to the conductor 56a, which leads to the conductor 5S and to one terminal of the generator eld 3c for controlling the motor 3 for rotating the platform 2. With respect to the switch element 53, seen in dotted line position 43h, effecting automatic control of the sighting target, the switch 43 now connects the conductor 51 from the sighting target motor 29 to the conductor 8| which alsol has a plurality of parallel branch conductors Sla leading to the slider `contacts 62 of the sighting target controlling potentiometers 63 for the respective 90, 45, 22.5, 11.25 and 0 simulated attacks. Each of the branch conductors Sla has a normally opened control switch 54 therein for interrupting the current between the potentiometer 63, connected to that branch, and the sighting target motor 25. Conductors 56 and 51 are connected to the power source 43 and 4|, such as the plus and minus poles of a battery, or a, generator (not shown), and lead respectively to the outside 01 end taps of the potentiometers B and 5|, conductors 66a and 61a being connected respectively to the conductors 66 and 61, and lead to the current reversing switches 68 and ;;a switch in the same circuitk so that once the.

8 E9. These switches are simultaneously movable to connect the conductors 56a and 67a respectively with either the conductors 61h and 68h or the conductors 68h .and 61h, for reversing the polarity to the terminals of the potentiometers 53 and 58.

A timer driving motor for actuating the respective slider contacts 5|! and 52 of the potentiometers 58 and E3 is provided and also for closing the associated switches 59 and B4, later to be described. This timer motor is indicated at 10 in the wiring diagram of Fig. 5, current being supplied to the motor 1] through the conductors 55d and 87d. A switch 1| is interposed in the conductor 61d for interrupting the current to the motor IQ when this switch is open. The means for initiating the operation of the timer motor it is a manual circuit closing of the switch as indicated at 1|. l

Before describing my automatic timer, as best seen in Figs. 2, 3, and 4, it will be noted that -they potentiometers 58 and 53 may be connected in4l the respective platform and sighting target motor controlling circuits by the closing oi the associated control switches 59 or 54, and during ther time the selected potentiometers are in the energizing circuit the positions of the respective slider contact arms with respect to the center' taps determine the rate of rotation of the platform 2 and the rate of travel of the sighting tar-get 32. Relative movements of the slider arms 55 and 52 also change the individual speed rates of the platform and sighting target during such movements.

Referring again to Figs. 2, 3 and 4 the timer motor 'l5 incorporates a reduction gear train not shown) which drives a pinion 55a at a comparatively slow and constant speed. The drive pinion '.Ga meshes with a larger pinion I2 that is fixed on a timer shaft 13, suitably journalled in spaced brackets 'E4 and '15, as best selen in Fig. 2. The timer shaft '.'3 has a plurality of specially shaped cams |3a and '|379 fixed thereon for actuating the sliders G and G2 of the potentiometers 58 and 63. A fixed supporting rod 76 is provided and secured at its ends in the brackets- 'i4 and l5. This rod carries a plurality of levers and 1'8 freely journalled thereon, each lever having a roller 'i9 which rides on the periphery of one of the cam discs "13a, 73h. The levers as shown in Fig. 4 each carry an insulated switch contact plate 8), movable by its actuating cam member into contacting engagement with a Xcd contact terminal 8|. Leaf spring members 82 are secured to a xed rod B3, as best seen in Fig.l

4 for rocking the levers 'H and 'i8 clockwise to maintain the rollers 'I9 in contact with the pe-A riphery of the timer cams 73a and 13b as'they rotate.

Referring to Figs. 2 to 4, the levers 'I8 each have a rack segment 28a fixed thereon, meshing with a pinion 84 xed to one of the potentiometer slider arms 50 or 52 of the potentiometers 58 and 63, in the wiring diagram in Fig. 5. The timer motor l5 is of any conventional constant speed type that will cause rotation of the cam shaft 13 at a uniform speed, and the motor when started, should preferably rotate the shaft T3 a single revolution and then stop. The two switches may be connected in the motor operating circuit, under the control of the cams 3c.

and i3d so that one of the switches is open in a starting circuit, which circuit is closed by the starting switch 'Il while the other cam controls laterne-'oo starting switch 'H iis fclosed, the cam 13e :actuated Aby Athe timer shaft i3 closes the timer circuit .and .maintains 'the .circuit :closed :until vthe cern discs `rotate :sufficiently for 'the Aconiiguration of the `:cam to again .open the `timer circuit and stop the timer. (This complete cycle of operation oc- Kcurs with .respect to all of the potentiometers but, depending .upon which :of the platform and sight target potentiometer circuits are closed by vthe manual closing yof .the desired type `of attack angle switches 5.9 and Gli, only Vthe epotentiometers controlled -by these switches are connected into the .operating circuits which control .the platform and sight target motors 3 29. The `respective cam members 'i3d and 13b `for operating the slider arms associated with the potentiometers which are switched into the circuit by the closing of fthe switches 159 and fet determines the sighting problem. vSince the `contours lof the vcam membersfor the `different petentiometer slider actuations are all formed differently, for the vdesired platform and sighting 'target `motor operations, to `each simulate one type of angle attack, such las 90, 45, etc., and that the respective connecting of these potenti- Aom'eters in the .circuit is by the selected pairs of switches '9 and 621, the closing -of the left-hand switches 59 and 64 in the 'wiring diagram conditions the device for a vsubsequent 90 angle `attack actuation. When the 'starting switch 'i-"I yis closed to 'start the timer, the potentiometer arms are all actuated by the timer cams i3d and i329, but only the platform and sighting target ipotentiometers Which were selected `and 'connected in the control circuit by the manually selected attack angle v'switches 59 and 6B will lbe effective, causing the platform to be rotated and the sighting target to be moved toward the platform and turret, at definite predetermined ratios with respect to each other, as .controlled by the predetermined contour of lthe selected platform and sighting tar-get control cams.

The instructors control panel discloses 4switches for simulating the attacks from angles of 90, 45, 22.5, '11.25 and 0. The Wiring diagram only discloses two sets of these automatic potentiometer controls, namely, the 90 and 45 angle attack controls, the other attack angle potentiometers having been .omitted from the drawing, since they are connected to the respective conductors Gib, 56a, 54, EB, vtl and 65a in identically the same manner as the potentiometers '58 and 63 as shown in the drawings. Likewise in the fragmentary views of the timer mechanism, Figs. 2 to 4, there are only two sets i of potentiometers and control cams disclosed, the contour of which controls the platform and sight target motors for the two different attack angles. In order to provide controls for the other vangles indicated, three additional sets -of control cams, notshown, are provided.

In the operation, referring to Fig. l1, the sighttarget `32 .is-disposed on the remote end of the track .frame .farthest away from the gunner in the turret 1 who is to fsight his guns .on the sighting target 32. The instructor .at his con` trol kstation now selects the ,problem to be `presented te the gunner. For insta-nce, if va 90 approach attack is selected, the 90 attack angle switch is closed connecting the `two slider arms of .the `two ,potentiometers farthest to the left (in Fig. 5T) of the potentiometer :groups 68 4and 63, ato the fcontrolling circuits of the respective sighting target and plat-form .-motors, so that these circuits fare conditioned for operation. To

.start the automatic cycle the instructor now `closes `the action or starting switch ll., closing the circuit to the timer motor i0. Operation of this motor rotates the timer shaft 'I3 and the cams 13a, 13h, 13e and 13d xed thereon, actu- .ating the respective levers 'l1 and i8. Movement of the levers 'H operates the switches 8D in the desired order, and, .as the timer continues to operate, the controlling circuits for the respective platform and sighting target motors are energized. A-s the cams 73a and isb are rotated, the potentiometer sliders are shifted from the center Vtap position toward `the end .taps at a predetermined rate, but not necessarily a constant rate since this depends upon the contour of the .associated cams .for the :controlling potentiometers, as selected by the energizing 4switches 5S and 64. The movement of the slider 60 of the selected .potentiometer `:58 causes the platform lto be rotated at a predetermined rate, -while the movement of the selected potentiometer sliders 62 controls the rate of movement `of the sighting target plane .from the `outer end of .the track toward .the gunner.

The combined movement of the platform and sighting target, when the sighting target is viewed by a .gunner through his gun sights, simulates a definite pursuit curve being fiown by the attacking plane toward a bomber carrying the gunner.

While the construction shown and described accomplishes the objects of the invention as herein stated, this disclosure is not intended to confine the .invention to the specific embodiment illustrated as various modifications may be made without departing from the spirit of the `invention as set forth in the following claims. ,y

Iclaim:

1. In `an aircraft gunnery practice range having a stationary scoring target, a support, a platform rotatable on the support on a substantially vertical axis, a lturret mounted on the platform for independent rotation, guns carried by the turret having a sighting means therefor with a sighting axis elevated above the line of fire of the guns and directable incident to rotation of the turret and the elevation or depression of the guns, a sighting target airplane movable in a substantially vertical plane toward the rotary axis of the platform during rotation thereof, whereby relative predetermined different rates of rotative displacement of the sighting `axis incident to predetermined different rates o'f rotative displacement of the platform, and predetermined different rates of movement of the sighting target airplane toward the sighting means from an 'initial position remote from the rotary axis of the platform, simulates a pursuit plane ying toward the sighting means on different predetermined pursuit curves, simulating a bomber in flight when attacked by the pursuit plane, and relatively separate power means connected to the platform for independently rotating the platform and connected to the sighting target airplane moving the sighting target airplane toward. 'said `platform axis, in the target sighting axis, when the line of lire of the guns are trained on the scoring target; the improvement 'which `includes lan improved control device comprising a first group of independent speed control devices, each selectively and independently connectabie with the power Vmeans for rotating the platform at a predetermined different rate, a second group of independent speed control devices, `eachof which is selectively and independently connectable Awith the power means for moving the sighting target at a predetermined different rate toward the platform axis, and manually controllable selector means operable to simultaneously connect predetermined pairs of said independent speed control devices one from said rst group and one from the second group respectively to the platform and sighting target moving power means, for rotating the platform and moving the sighting target simultaneously, at predetermined different definite ratios, for simulating definite predetermined pursuit curves flown by a pursuit plane attacking the bomber from different definite angles when the sighting target is viewed from the platform through the sighting means.

2. In a gunnery trainer device, the combination with a fixed support, a platform rotatable thereon about a fixed axis, a directable gun unit mounted on the platform having gun sighting means therefor with its sighting axis adjusted in elevation above the line of fire of the gun unit, a scoring target fixed at a remote-point with respect to the rotary axis of the platform, a movable sighting target disposed to travel from a different remote point toward the platform axis in line with the gun sighting axis of the gun sighting means when the line of fire of the guns are trained on the scoring target, regulatable power means for rotating the platform about its axis with respect to the movement of the sighting target toward the platform axis, regulatable power means for moving the sighting target from said different remote point toward the platform at different rate during rotation of the platform; a unitary control device for simultaneously controlling the rate of rotation of the platform and the rate of movement of the sighting target toward the platform, said unitary control device comprising a rst group of independent power control devices each selectively connectable with the platform rotating power means. to rotate the platform about its axis at a predetermined definite different speed, and a second group of independent power control devices each selectively connectable with said sighting target advancing power means to move the Sighting target toward the platform Ifrom the different remote point at a predetermined denite different speed, and manually operable selector means movable to connect predetermined pairs of said power control devices, one from each group, to the respective platform rotating and sighting target advancing power means. for rotating the platform about its axis and moving the sighting target toward the plat- 'form axis at a plurality of definite predetermined rates with respect to each other.

3. In a gunnery trainer device having a support, a platform rotatable thereon about a vertical axis, adirectable gun unit mounted on the platform for independent rotation about said axis having sighting means therefor with its sighting axis adjusted to a predetermined elevation relative to the line of fire of the gun unit, a scoring target fixed with respect to the rotary axis of the platform at a remote point there from, a movable sighting target disposed to travel from a different remote point toward the platform axis in the sighting axis of the gun sighting means when the line of re of the gun unit is trained on the scoring target, adjustable power means for rotating the platform at different rates with respect to the movement of the sighting target toward the platform, power means for moving the sighting target toward l2 the platform at different rates during rotation of the platform; the improvement comprising a control device for selectively controlling the rate of rotation of the platform relative to the rate of movement of the sighting target toward the platform comprising a motor driven timer device having a uniformly driven cam shaft, a plurality of control cams xed on said shaft, each cam having a different predetermined contour, a plurality of actuating levers pivotally positioned adjacent said cams each lever disposed in actuating engagement with one of said cams,

individual variable power control means for controlling the rate of rotation of the platform and the rate of movement of the sighting target and operable by each of said levers and selectively connectable with the platform rotating and sighting target moving power means to selectively rotate the platform and move the sighting target towards the platform at definite predetermined diiferent rates of movement.

4. In a gunnery trainer device having a support, a platform rotatable thereon about a vertical axis, a directable gun unit mounted on the platform for independent movement having sighting means with its sighting axis adjusted in elevation to a predetermined degree relative to the line of fire of the gun unit, a scoring target fixed at a remote point with respect to the rotary axis of the platform, a movable sighting target disposed to travel from a different remote point toward the platform in the sighting axis of the gun sighting means when the line of fire of the gun unit is trained on the scoring target, electrically operable power means for rotating the platform with respect to the direction of movement of the sighting target, electrically operable power means for advancing the sighting target toward the platform during the rotation of the platform, including separate energizing circuits for the platform rotating means and the sighting target moving power means; a power driven timer device for variably energizing said energizing circuits comprising a first group of potentiometers selectively connectable in the energizing circuit for the platform rotating electrical power means to rotate the platform at different rates, a second group of potentiometers selectively connectable in said energizing circuit for the sighting target moving power means for advancing the sighting target toward the platform at different rates, an electrically operable motor driven cam shaft having a plurality of cams fixed thereon, one for each potentiometer, actuating means between each cam and a potentiometer including an operating connection for operating the potentiometer to control the electrical potentiometer in its associated energizing circuit in a predetermined ratio to the contour of the operating cam for that potentiometer, manually selectable switch means in each platform rotating power energizing circuit, manually selectable switch means in each sighting target moving power energizing circuit for closing the circuits selectively, whereby the operation of selected pairs of the switch means connect predetermined potentiometers in the platform rotating control circuit and in the sighting target moving control circuit for rotating the platform about its axis and moving the sighting target toward the platform from the said different remote point at predetermined definite ratios with respect to each other, and energizing circuit for operating the cam shaft motor, and switch means in said last energizing circuit for closing the circuit and initiating the operation of the timer while the selected potentiometers are connected in the associated platform rotating and sighting target moving electrical energizing circuits.

5. In an aircraft gunnery practice range comprising a relatively fixed support, a power driven platform rotatable on a vertical axis on the xed support, an aircraft gun turret independently rotatable about said vertical axis on the platform, a miniature sighting target airplane movable from a remote point toward the vertical axis of the platform during rotation thereof for simulating a pursuit plane flying a pursuit curve when attacking a bomber, when the sighting target airplane is observed from within the turret while the platform is rotating, the bomber being simulated by the platform and turret thereon ,and the pursuit plane being simulated by the sighting target airplane, a gunnery instructors control station remote Vfrom the platform and the sighting target for controlling the relative movements of the platform and sighting target airplane; the improvement which comprises a plurality of separate groups of speed control devices the devices of one group being selectively connectable to the platform power rotating means for rotating the platform at definite different rates and the other group to the sighting target moving means, each control device in the first group selectively determining the rate of rotating the platform at a definite different predetermined speed and each control device in the second group determining the rate of movement of the sighting target toward the turret axis at a. selectively different predetermined denite speed, and manual selector means at said inystructors control station for selectively connecting predetermined pairs of said separate speed control devices one from each group to the platform and sighting target power means to selectively rotate the platform and move the sighting target toward the platform axis at denite predetermined rates with respect to each other.

6. In a gunnery trainer device, the combination with a support, a platform rotatable thereon about a fixed axis, a directable gun unit mounted on the platform having sighting means therefor with its sighting axis adjusted in elevation relative to the line of fire from the gun unit, a stationary scoring target fixed with respect to the platform axis at a remote point, a movable sighting target disposed to travel from a different remote point toward the platform axis in the sighting axis of the gun sighting means when the line of nre of the guns is trained on the scoring target, regulatable platform rotating power means for rotating the platform at different rates with respect to the position of the sighting target, regulatable sighting target advancing power means operatively con- 14 nected to the sighting target for moving the sighting target from said different remote point toward the platform at different rates during rotation of the platform; a control device for simultaneously determining the rate and direction of rotation of the platform and the rate of movement of the sighting target toward the platform axis, said control device comprising an operation timer having a uniformly driven timer shaft, a first group of independently adjustable power control elements simultaneously driven by said timer shaft and selectively connectable to the platform rotating power means, and a second group of independently adjustable control elements simultaneously driven by said timer shaft and selectively connectable to the sighting target advancing power means for actuation thereof, control means movable to selectively connect any one of the adjustable power control elements of the first group to the power means for rotating the platform at predetermined different rates and connect any one of the adjustable power control elements of the second group with the sighting target advancing power means for advancing the sighting target toward the platform at predetermined different rates, actuated by the timer shaft to combine rotation of the platform about its axis and movement of the sighting target from the said different remote point toward the platform at predetermined definite relatively different predetermined rates, for simulating the appearance of predetermined attacks of a pursuit plane on a bomber from definite predetermined different angles relative to the flight axis of the bomber when the sighting target is observed through the sighting means during simultaneous rotation of the platform and movement of the sighting target toward the platform axis at the said predetermined different rates.

CLARENCE W. CLARKSON, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 12,916 Fiske Feb. 9, 1909 684,105 Roscusvard Oct. 8, 1901 1,313,685 Gilbert Aug. 19, 1919 1,865,828 Buckley July 5, 1932 1,939,706 Karnes Dec. 19, 1933 2,224,564 De Silva Dec. 10, 1940 2,364,070 Haile "\Dec. 5, 1944 2,373,313 Jeandron Apr. 10, 1945 2,387,153 Johnson Oct. 16, 1945 2,387,749 Darnell Oct. 30, 1945 2,428,432 Park Oct. 7, 1947 2,457,832 Poorman Jan. 4, 1949 

